SWITCH SUB WITH TWO WAY SEALING FEATURES AND METHOD
There is a switch sub adapter configured to connect a switch sub to a perforating gun assembly. The switch sub adapter includes a body having first threads that connect to the switch sub and second threads that connect to the perforating gun assembly; a first internal chamber formed at a first end of the adapter; a second internal chamber formed at a second end of the adapter; a conduit connecting the first internal chamber to the second internal chamber; and a dart having a tip part located in the conduit and a base part located in the second internal chamber.
Embodiments of the subject matter disclosed herein generally relate to downhole tools related to perforating and/or fracturing operations, and more specifically, to a switch sub that protects the electronics located inside the switch sub from detonation debris, wellbore fluid, and/or a pressure wave produced by the detonation of a perforating gun assembly.
Discussion of the BackgroundIn the oil and gas field, after a well 100 is drilled to a desired depth H relative to the surface 110, as illustrated in
The step of perforating the well requires to lower into the well 100 the perforating gun assembly 114, which is electrically and mechanically connected at one end to a wireline 118. The other end of the perforating gun assembly 114 is connected to a setting tool 120. The setting tool is configured to hold the plug 112 and to set the plug at the desired location, when instructed.
The above operations may be repeated multiple times for perforating and/or fracturing the casing at multiple locations, corresponding to different stages of the well. Note that in this case, multiple plugs 112 and 112′ may be used for isolating the respective stages from each other during the perforating phase and/or fracturing phase.
During fracturing or other completion operations, it is desired to completely shut down one or more stages of the well. This is achieved by installing one or more plugs. For each stage, a corresponding part of the casing needs to be perforated before the fracturing operations. One or more perforating gun assemblies 114 may be used for each stage for perforating the casing.
If plural gun assemblies are used, as illustrated in
In
Thus, it is desirable to have a switch sub that protects the inside electronics so that, after a perforating process is completed, both the switch sub and its electronics can be reused.
SUMMARYAccording to an embodiment, there is a switch sub adapter configured to connect a switch sub to a perforating gun assembly. The switch sub adapter includes a body having first threads that connect to the switch sub and second threads that connect to the perforating gun assembly; a first internal chamber formed at a first end of the adapter; a second internal chamber formed at a second end of the adapter; a conduit connecting the first internal chamber to the second internal chamber; and a dart having a tip part located in the conduit and a base part located in the second internal chamber.
According to another embodiment, there is a dart puck configured to close a switch sub. The dart puck includes a body having a conduit that communicates with an internal chamber, the conduit having a smaller diameter than the internal chamber; and a dart located with a tip part inside the conduit and with a base part inside the internal chamber. The dart is configured to seal the conduit so that a pressure wave generated on one side of the dart puck does not propagate through the conduit to another side of the dart puck.
According to still another embodiment, there is a switch sub configured to connect an upstream perforating gun assembly to a downstream perforating gun assembly. The switch sub includes a body having external threads, at a first end, which connect to the downstream perforating gun assembly, and external threads, at a second end, which connect to the upstream perforating gun assembly; an internal chamber; an electrical device located inside the internal chamber; a dart puck configured to close, at the second end, the internal chamber; and a dart located inside the dart puck and configured to seal the dart puck so that a pressure wave generated by the upstream perforating gun assembly does not propagate through the dart puck to damage the electrical device.
According to yet another embodiment, there is a method of using a switch sub that connects an upstream perforating gun assembly to a downstream perforating gun assembly. The method includes placing an electrical device inside a chamber of the switch sub; attaching the switch sub to the downstream perforating gun assembly; adding a sealing mechanism to one end of the chamber, the sealing mechanism having a dart that seals the chamber so that a pressure wave generated by the upstream perforating gun assembly does not propagate into the chamber to damage the electrical device; attaching the upstream perforating gun assembly to the switch sub; lowering the switch sub to a desired depth inside a well; and activating the upstream perforating gun assembly without damaging the electrical device.
According to another embodiment, there is a device for protecting an internal chamber of a switch sub from a blast of a gun. The device includes a slab having a through passage and a projectile loosely located with a tip part inside the passage and with a base part outside the passage. The projectile is configured to seal the passage so that a pressure wave generated by a first perforating gun assembly located on one side of the slab does not propagate through the passage toward a second perforating gun assembly located on another side of the slab.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one or more embodiments and, together with the description, explain these embodiments. In the drawings:
The following description of the embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. The following embodiments are discussed, for simplicity, with regard to attaching two perforating gun assemblies to each other through a switch sub. In the following, the terms “upstream” and “downstream” are being used to indicate that one gun assembly may be situated above and below, respectively, in relation to a given element in the well. However, one skilled in the art would understand that the invention is not limited only to the upstream gun assembly or only to the downstream gun assembly, but in fact can be applied to either gun assembly. In other words, the terms “upstream” and “downstream” are not used in a restrictive manner, but only to indicate, in a specific embodiment, the relative positions of the gun assemblies. Further, the embodiments discussed herein are applicable to other components that need to be connected through a switch sub.
Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.
A typical switch sub is manufactured to have an internal chamber in which one or more electronic parts are located. The switch sub is designed to pressure seal one end of the internal chamber, from a downstream perforating gun assembly, so that the detonation of the shaped charges of the downstream perforating gun assembly do not damage the electronics. However, the internal chamber is not pressure sealed from the upstream perforating gun assembly. Thus, when a detonation signal is received from the wireline, the electronics inside the switch sub initiate the detonation of the upstream perforating gun assembly. After the shaped charged are detonated, the debris from the gun assembly, the wellbore fluid, and/or pressure wave produced by these detonations enter the internal chamber of the switch sub and damage the electronics. Thus, according to an embodiment, the switch sub is provided with a seal mechanism (e.g., adapter and dart or dart puck and dart) at the end facing the upstream perforating gun assembly, to pressure seal both ends of the internal chamber to protect the electronics inside. The term “puck” is used herein to mean an element having a certain surface that is used to cover an opening in a switch sub. The puck may have any shape and/or size as long as the features discussed later can be implemented in such element. The puck may be made of any appropriate material. For example, the puck may be a slab of metal. The term “dart” is used herein to mean an element that can partially enter inside a conduit formed in the puck. Under normal conditions, the dart can enter only partially inside the conduit. However, under increased pressure, the dart can deform and enter more inside the conduit. The dart may have any shape and/or size as long as it fulfils the features noted above. For example, the dart may be a projectile.
According to an embodiment illustrated in
Switch sub 300 has an internal chamber 302 formed in a body 306. Chamber 302 is in communication, at the first end 300A, with a bore 304 formed in a bulkhead 305. While bore 304 is fully occupied by an igniter 308 (other devices may be present in the bulkhead instead of the igniter or no device) in
Returning to
Inside the internal chamber 302 of the switch sub 300, there is a switch 316 that is electrically connected by one or more wires 317 to igniter 308 and by one or more wires 319 to the upstream perforating gun assembly 350. Switch sub 300 also has an opening 300C through which various electrical connections between the various wires may be made. A nut (not shown) may be attached (e.g., with threads) to opening 300C for sealing the internal chamber 302.
Adapter 330 has a body 334 that houses an internal chamber 336, located at one end 330A of the adapter, and the internal chamber 336 is configured to communicate with the internal chamber 302 of the switch sub. In one application, internal chamber 336 and internal chamber 302 have the same internal diameter. Internal chamber 336 (called herein the first internal chamber) narrows toward the middle of the body 334, into a narrow conduit 338, as illustrated in more detail in
Returning to
Dart 342 is shown in
Thus, when the upstream perforating gun assembly is detonated, a pressure blast from the gun enters into the second internal chamber 340, through the passage 344A, and pushes the dart 342 into the conduit 338. When this happens, the dart 342 is propelled into the conduit 338 as illustrated in
In one embodiment, the dart 342 may have an internal channel 342C, as illustrated in
The embodiments discussed above have the advantage that the traditional switch subs can be used with the discussed adapter for protecting the switch or other electronics located inside the switch sub. However, the length of the entire assembly is increased, e.g., by about 4″, due to the length of the adapter. For some situations, this result is undesired.
Thus, another embodiment is now discussed that does not use the adapter 330 for sealing both ends of the switch sub.
Dart puck 760 is shown in more detail in
Note that
In still another embodiment, as illustrated in
In one embodiment, lip 868 is fully located inside slot 802, i.e., it is fully located inside the switch sub 300. To remove or attach the dart puck 860 to the switch sub 300, the internal chamber 870 may be formed to have a specific internal shape (e.g., hex shape) so that a dedicated tool may be inserted into the chamber to screw or unscrew the dart puck. Alternatively, notches may be formed in the lip 868 for allowing a dedicated tool to engage the dart puck.
A method of using a switch sub that protects inside electronics from damage from both upstream and downstream directions is now discussed with regard to
The disclosed embodiments provide methods and systems for preventing electronics located inside a switch sub from being damaged by a detonation of an adjacent perforating gun assembly. It should be understood that this description is not intended to limit the invention. On the contrary, the exemplary embodiments are intended to cover alternatives, modifications and equivalents, which are included in the spirit and scope of the invention as defined by the appended claims. Further, in the detailed description of the exemplary embodiments, numerous specific details are set forth in order to provide a comprehensive understanding of the claimed invention. However, one skilled in the art would understand that various embodiments may be practiced without such specific details.
Although the features and elements of the present exemplary embodiments are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the embodiments or in various combinations with or without other features and elements disclosed herein.
This written description uses examples of the subject matter disclosed to enable any person skilled in the art to practice the same, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims.
Claims
1. A switch sub adapter configured to connect a switch sub to a perforating gun assembly, the switch sub adapter comprising:
- a body having first threads that connect to the switch sub and second threads that connect to the perforating gun assembly;
- a first internal chamber formed at a first end of the adapter;
- a second internal chamber formed at a second end of the adapter;
- a conduit connecting the first internal chamber to the second internal chamber; and
- a dart having a tip part located in the conduit and a base part located in the second internal chamber.
2. The switch sub adapter of claim 1, wherein the dart is loosely located in the conduit and the second internal chamber.
3. The switch sub adapter of claim 1, wherein an exterior diameter of the tip part of the dart is smaller than an exterior diameter of the base part of the dart.
4. The switch sub adapter of claim 1, wherein the base part of the dart has a diameter larger than a diameter of the conduit so that the base part does not fit inside the conduit.
5. The switch sub adapter of claim 4, wherein the dart is made of a soft metal that deforms under pressure so that at least a portion of the base part squeezes inside the conduit to seal the conduit.
6. The switch sub adapter of claim 1, wherein one or more wires associated with an electric device located within the switch sub pass from the first internal chamber to the second internal chamber through the conduit.
7. The switch sub adapter of claim 6, wherein the dart is not electrically connected to the one or more wires.
8. The switch sub adapter of claim 6, wherein the dart has a conduit through which the one or more wires pass by.
9. The switch sub adapter of claim 6, wherein the dart is made of a soft metal that deforms under pressure so that at least a portion of the base part squeezes inside the conduit to seal the conduit and also severs the one or more wires.
10. The switch sub adapter of claim 1, wherein the dart seals the conduit so that a pressure wave generated by the perforating gun assembly, at either end of the switch sub, does not damage an electric device located inside the switch sub.
11. A dart puck configured to close a switch sub, the dart puck comprising:
- a body having a conduit that communicates with an internal chamber, the conduit having a smaller diameter than the internal chamber; and
- a dart located with a tip part inside the conduit and with a base part inside the internal chamber,
- wherein the dart is configured to seal the conduit so that a pressure wave generated on one side of the dart puck does not propagate through the conduit to another side of the dart puck.
12. The dart puck of claim 11, wherein the internal chamber is closed with a retaining nut for maintaining loosely the dart inside the internal chamber.
13. The dart puck of claim 11, wherein the dart is located in its entirety inside the dart puck.
14. The dart puck of claim 11, wherein an exterior diameter of the tip part of the dart is smaller than an exterior diameter of the base part of the dart.
15. The dart puck of claim 11, wherein the base part of the dart has a diameter larger than a diameter of the conduit so that the base part does not fit inside the conduit.
16. The dart puck of claim 15, wherein the dart is made of a soft metal that deforms under pressure so that at least a portion of the base part squeezes inside the conduit to seal the conduit.
17. The dart puck of claim 11, wherein one or more wires associated with an electric device located inside the switch sub pass through the conduit and the internal chamber.
18. The dart puck of claim 17, wherein the dart is not electrically connected to the one or more wires.
19. The dart puck of claim 17, wherein the dart has a conduit through which the one or more wires pass by.
20. The dart puck of claim 17, wherein the dart is made of a soft metal that deforms under pressure so that at least a portion of the base part squeezes inside the conduit to seal the conduit and also severs the one or more wires.
21. The dart puck of claim 11, wherein the body is located between the switch sub and a perforating gun assembly that generates the pressure wave.
22. The dart puck of claim 11, wherein the body is attached with a thread to the switch sub.
23. The dart puck of claim 11, wherein the body is located in its entirety inside the switch sub.
24. The dart puck of claim 11, wherein the body has a lip that fits into a slot of the switch sub.
25. A switch sub configured to connect an upstream perforating gun assembly to a downstream perforating gun assembly, the switch sub comprising:
- a body having external threads, at a first end, which connect to the downstream perforating gun assembly, and external thread, at a second end, which connect to the upstream perforating gun assembly;
- an internal chamber;
- an electrical device located inside the internal chamber;
- a dart puck configured to close, at the second end, the internal chamber; and
- a dart located inside the dart puck and configured to seal the dart puck so that a pressure wave generated by the upstream perforating gun assembly does not propagate through the dart puck to damage the electrical device.
26. The switch sub of claim 25, wherein the dart puck is located inside the upstream perforating gun assembly.
27. The switch sub of claim 25, wherein the dart puck is located inside the switch sub.
28. A method of using a switch sub that connects an upstream perforating gun assembly to a downstream perforating gun assembly, the method comprising:
- placing an electrical device inside a chamber of the switch sub;
- attaching the switch sub to the downstream perforating gun assembly;
- adding a sealing mechanism to one end of the chamber, the sealing mechanism having a dart that seals the chamber so that a pressure wave generated by the upstream perforating gun assembly does not propagate into the chamber to damage the electrical device;
- attaching the upstream perforating gun assembly to the switch sub;
- lowering the switch sub to a desired depth inside a well; and
- activating the upstream perforating gun assembly without damaging the electrical device.
29. The method of claim 28, wherein the sealing mechanism is an adapter located between the switch sub and the upstream perforating gun assembly.
30. The method of claim 28, wherein the sealing mechanism is a dart puck.
31. The method of claim 30, further comprising:
- closing the dart puck with a retaining nut to maintain loosely the dart inside the dart puck.
32. The method of claim 30, wherein the dart is located in its entirety inside the dart puck.
33. The method of claim 30, wherein the dart puck is attached with a thread to the switch sub.
34. The method of claim 30, wherein the dart puck is located in its entirety inside the switch sub.
35. The method of claim 30, wherein the dart puck has a lip that fits into a slot of the switch sub.
36. A device for protecting an internal chamber of a switch sub from a blast of a gun, the device comprising:
- a slab having a through passage; and
- a projectile loosely located with a tip part inside the passage and with a base part outside the passage,
- wherein the projectile is configured to seal the passage so that a pressure wave generated by a first perforating gun assembly located on one side of the slab does not propagate through the passage toward a second perforating gun assembly located on another side of the slab.
37. The device of claim 36, wherein the slab has an internal chamber that houses the base part of the projectile.
38. The device of claim 36, wherein a switch sub is located between the slab and the second perforating gun assembly.
39. The device of claim 36, wherein the switch sub houses a switch and the slab and the projectile protect the switch from debris, wellbore fluid or a pressure wave generated by one of the first and second perforating gun assemblies.
40. The device of claim 36, wherein the internal chamber is closed with a retaining nut for maintaining loosely the projectile inside the internal chamber.
41. The device of claim 36, wherein the projectile is located in its entirety inside the slab.
Type: Application
Filed: Nov 9, 2017
Publication Date: May 17, 2018
Patent Grant number: 11208873
Inventor: Shelby Lee SULLIVAN (Minot, ND)
Application Number: 15/808,290